How do I know if my internet explorer 10 is 32 or 64 bit?

I have Windows 7 home premium sp1. Up to a few days ago I had ie9 in 32 and 64 bit. During an automatic updating process a few days ago ie10 was installed. How do I know whether it is 32 or 64 bit. Why can't I have 32 and 64 bit in ie10 just like I had in ie9. Thank you. Stieve